This invention relates to a fuel filling system for diesel powered vehicles.
Internal combustion engines are powered by three main fuels. These are petroleum fuel in leaded or unleaded form (hereinafter referred to as leaded and lead free fuel respectively), and diesel fuel.
Petrol is dispensed from forecourt pumps having nozzles of circular cross-section and into filler orifices on vehicles also of circular cross-section. The filler orifice on vehicles powered by lead free fuel are of smaller diameter than the filler orifices of vehicles powered by leaded fuel. The nozzles of forecourt pumps dispensing lead free fuel are of smaller diameter than the nozzles of forecourt pumps dispensing leaded fuel. The nozzles of forecourt pumps dispensing leaded fuel are of greater external diameter than the internal diameter of the filler orifices on vehicles powered by lead free fuel so that the leaded fuel supply nozzles do not fit into the filler orifices of vehicles powered by lead free fuel.
Diesel fuel is also dispensed through nozzles of circular cross-section and into filler orifices also of circular cross-section. The size of the filler orifice of diesel powered vehicles permits the entry of both leaded and lead free fuel supply nozzles. This is a frequent cause of problems, particularly with drivers unused to diesel powered vehicles as they can fill their vehicles with petrol through ignorance or carelessness. The reverse also happens with diesel being put into petrol powered vehicles. This results in an expensive and time-consuming operation to remove the fuel and purge the system. The operation may involve more than 50 liters of volatile petrol with a degree of risk involved in the workplace.
The present invention seeks to overcome the aforementioned drawback.
According to the present invention there is provided a fuel filling system for diesel powered vehicles, comprising a diesel fuel filler orifice on the vehicle for receiving diesel fuel from a diesel fuel supply nozzle, the diesel fuel filler orifice being of non-circular cross-section and having a minimum internal dimension which is less than the external diameter of a traditional lead free fuel pump nozzle.
Preferred and/or optional features of the invention are set forth in claims 2 to 9.
The invention will now be more particularly described, by way of example, with reference to the accompanying drawings.